Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

First 405nm Build with a LM317 custom driver - Voltage help!

H

He So Pringles

0
Joined
Feb 1, 2013
Messages
7
Points
0
Hi there guys! So I'll start by saying I'm very new to building lasers, so this forum included, and I would love to be apart of it. I'll appreciate any bit of help I can get or even "critical" advice.

So I'm starting my first build with a custom made driver, I'm just using the basic LM317 driver build that I'm seeing all over the site. I'm uncertain what to look at though when determining the battery voltage I should be using.

I'm using a 405nm Diode and I'm using a 10 ohm resistor in my Driver to create a current of 1.25mA. Any help determining the battery voltage I should be using?
 





Cube777

Cube777

0
Joined
Jul 22, 2012
Messages
426
Points
28
The 405nm diodes has a rather high Vf, i think two Li-ions ought to do it. If it still does not provide enough current, switch to a LM2941. It has a lower voltage drop.
 
Cube777

Cube777

0
Joined
Jul 22, 2012
Messages
426
Points
28
^If he used a 10ohm resistor like he said it would equal 125mA which is more than enough for a PHR
 
T

Things

0
Joined
May 1, 2007
Messages
7,517
Points
0
125mA is probably on the verge of a bit too high for a PHR, I'd stick to 90-100mA max if you want a decent stable lifetime.
 
jimdt7

jimdt7

0
Joined
Feb 5, 2011
Messages
1,893
Points
48
Since you are using a PHR diode, you'd better feed it with ~85-100mA for long living life :beer:

Jim
 
H

He So Pringles

0
Joined
Feb 1, 2013
Messages
7
Points
0
Oh, my bad. I meant 125mA, thank you for understanding.
Here is the page I purchased the diode from. HighTechDealZ - 405nm PHR805T Blu Ray Laser Diode in Aixiz Module

It labeled it as 120mA current, but if you're all recommending lower than perhaps I'll just wire two 10 Ohms in series.

Thank you for the battery recommendation. Helps me a ton!

Also, I'm using the basic LM317 build where the resistor is hooked from the Vout and adjustment, and a lead going from LD+ to adjustment, Battery + to Vin, and LD - to battery -.
Is this correct if I'm not involving a capacitor?
 
Last edited:
H

He So Pringles

0
Joined
Feb 1, 2013
Messages
7
Points
0
One more question. Do the Li-ion batteries have a holder? I can't seem to find one (maybe I suck at looking) and the host I'm using isn't a pen or flashlight host so I can't use a spring.
Any other way you would recommend wiring batteries without a holder?
 
H

He So Pringles

0
Joined
Feb 1, 2013
Messages
7
Points
0
Thank you all so very much. This community is great and I'm grateful for the feedback!

I believe this is my last question. If I were to run a current of 100mA to the diode with the module shown in the link I posted earlier, will I require a heat sink or does the module satisfy the needs for heat absorption already?

I'm kinda iffy on when it's necessary to use a heat sink. The host I'm going to use isn't meant for constant run time, so the laser will be used in short burst.
 
You must log in or register to reply here.




Top